THURSDAY, Aug. 22, 2019 (HealthDay News) -- Everywhere you look, CBD products are for sale, and they may hold promise for treating chronic pain, opioid addiction and other conditions.

But a new review says more human clinical trials on the safety and effectiveness of cannabidiol (CBD) products are needed.

"There are many intriguing findings in pre-clinical studies that suggest CBD and hemp oil have anti-inflammatory effects and may be helpful with improving sleep and anxiety," said Dr. Brent Bauer, director of research for the Mayo Clinic Integrative Medicine program.

"But trials in humans are still limited, so it is too early to be definitive about efficacy and safety," he added in a Mayo Clinic news release.

There are a growing number of reports of liver injury in patients who've used CBD products, Bauer noted.

"Careful selection of a health care product is crucial, and though these products do not have [U.S.] Food and Drug Administration approval for therapeutic use, patients continue to ask for them and use them," he said. "Physicians need to become better informed about these products, and it's important that human trials examine issues of efficacy and safety."

Because many Americans are embracing CBD products, doctors should learn as much as possible about those products, Bauer suggested.

"We encourage physicians to not disregard their patients' interest in these products, and keep both a clinical curiosity and a healthy skepticism about the claims made," he said.

"Chronic pain management continues to challenge patients and physicians, and these therapies are a promising area that needs more research. For patients struggling with chronic pain, physicians taking time to listen to them and address their questions compassionately, but with an evidence-based approach, can help them make informed decisions," Bauer said.

The review found that limited regulation of CBD products is a concern for health care providers.

According to review co-author Dr. Karen Mauck, an internist at the Mayo Clinic in Rochester, Minn., "Other than Epidiolex -- a purified form of plant-derived CBD which was approved in 2018 for treatment of severe forms of epilepsy -- all other forms of CBD are not approved by the Food and Drug Administration, but are sold in a variety of formulations, including oral or topical oils, creams, sprays and tablets."

These formulations "contain variable amounts of CBD, may contain other active compounds and may have labeling inaccuracies. Before using CBD or hemp oils, it's important to consult with your physician about potential side effects and interactions with other medications," Mauck advised in the news release.

The review was published in the September issue of the journal Mayo Clinic Proceedings.